The present invention relates to a reinforced resin composition which is useful for automotive and electrical/electronic parts, among others.
Polycarbonate resin is known as a plastic material having the highest impact resistance of all engineering plastics as well as satisfactory heat resistance and is in broad use in a variety of applications where these characteristics are much valued. However, this resin has some drawbacks, namely poor chemical resistance, poor moldability, and thickness dependence of impact strength. On the other hand, theremoplastic polyester resin is excellent in chemical resistance and workability but poor in impact resistance and dimensional stability.
To make the most of the advantageous characteristics and make up for the drawbacks of such respective resins, a variety of compositions have heretofore been reported in the literature including Japanese Patent Publication Nos. 36-14035, 39-20434, 55-9435, 62-37671, 62-34792 and 62-13378, and Japanese Kokai Patent Publication Nos. 62-295951 and 63-83158, among others.
Thus, Japanese Patent Publication No. 36-14035 discloses a thermoplastic material comprising a 4,4'-dioxydiarylalkane polycarbonate and polyethylene terephthalate. J.P. Publication No. 39-20434 describes a resin composition comprising a 4,4'-dioxydiarylalkane polycarbonate, a polyolefin and a saturated polyester. J.P. Publication No. 55-9435 discloses a thermoplastic resin composition comprising an aromatic polyester, an aromatic polycarbonate and a butadiene graft copolymer. Described in J.P. Publication No. 62-37671 is a thermoplastic resin composition comprising a saturated polyester resin, a polycarbonate resin and a polyacrylate rubber-containing polymer as main components. J.P. Publication No. 62-34792 discloses a polycarbonate resin composition comprising a polycarbonate resin, a saturated polyester resin, a polyolefin resin and an acrylate rubber-containing vinyl polymer. J.P. Publication No. 62-13378 describes a polycarbonate resin composition comprising a polycarbonate resin, a saturated polyester resin, a polyolefin and an acrylatemethacrylate resin. Japanese Kokai Patent Publication No. 62-295951 proposes a polycarbonate resin composition comprising a polycarbonate resin, an aromatic polyester resin and an acrylate-butadiene graft copolymer. Furthermore, Japanese Kokai Patent Publication No. 63-83158 describes a resin composition comprising an aromatic polycarbonate, a thermoplastic polyester, a thermoplastic graft copolymer and a polyolefin.
However, none of these resin compositions are capable of providing all the characteristics required of automotive and other parts, namely sufficient impact resistance, heat resistance, chemical resistance, weather resistance and rigidity and, therefore, further improvements have been much awaited.
Furthermore, in some applications such as exterior parts of motor vehicles, where the clearance between individual parts must be minimal, a low linear coefficient of expansion is another essential requisite.
For insuring a low linear coefficient of expansion, attempts have been made to incorporate glass fiber or the like but such approaches tend to detract from impact resistance and moldability and cause a poor surface appearance of moldings, thus failing to provide fully satisfactory products.